L-α-Glycerylphosphorylcholine (L-α-GPC) is a naturally existing water-soluble phospholipid, which is the precursor for making acetylcholine and phosphatidylcholine in the body.
L-α-GPC has important medical applications, for example, it can enhance cognitive ability and even repair the partial damaged cognitive ability in early Alzheimer's disease. Furthermore, it can protect liver tissues from poisonous carbon tetrachloride and fatty acid penetration caused by high lipoprotein diet. It can also enhance body's resistance to high blood fat and protect blood vessels.
Currently, major methods in domestic and international research for preparing L-α-GPC are chemical synthesis, chemical hydrolysis, chemical alcoholysis and enzymatic hydrolysis. Methods of purification include solvent extraction, precipitation, recrystallization, and resin column chromatography.
L-α-GPC was firstly purified from cattle pancreatic (GSchmidt, J. Biochem, 1945, 161, 523) using a solvent extraction method, which was limited by the availability of raw materials and put a limit on the manufacturing scale. With the advance of new technologies, methods of chemical synthesis, chemical hydrolysis, and chemical alcoholysis were developed for making L-α-GPC. Purification methods such as calcium precipitation, recrystallization and resin column chromatography were also developed. However, these methods pose different levels of difficulties in preparing L-α-GPC with high yields and optical purity at industrial manufacturing scale. Furthermore, the chemical methods bring great challenges to the environment. Enzymatic synthesis process brings innovative ways in preparing L-α-GPC, but how to obtain high yields and purity using enzymatic methods is still very challenging.
In 1954, Mcarthur et al (U.S. Pat. No. 2,864,848) disclosed a method for the preparation of L-α-GPC using mercuric chloride hydrolysis of lecithin and removing by-products by precipitation in the form of mercury salts. A disadvantage of this method is that the residual mercury ion and raw phosphatidylcholine can not be easily removed and needs further purification through calcium precipitation and resin column chromatography, which not only increases the complexity of the preparation process, but also reduces the final yield.
In order to eliminate metal ion residues and increase the purity of the product, Cailo Myriam Gozzoli and Scolastico (UK. Patent GB. 2,058,792 A) used resin column chromatography to prepare L-α-GPC. The method comprises of a series of processes, such as alcoholysis, solvent extraction, ion exchange resin, and activated carbon decolorization, which results in products with massive toxic residue and low optical purity.
As such, there is a great need in the art for technologies to prepare L-α-GPC with high yields and optical purity in a cost-effective and environmentally friendly way. The present invention satisfies this need and provides other benefits as well.